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Aetheria SEMTO Engine ST-NF2 DIY Mini Metal Engine Kit, L2 Inline 2-Cylinder Air-Cooled DIY Assembly Engine with Starter Kit, SEMTO Engine Model Kit That Works Experiment STEM Hobby Toy

Qing Shuang Stirling Engine steam Engine Physics Experiment Popular Science Invention Toy Model Motor Model Educational Toy Generator Colorful LED, Silver, LxWxH 6.45×3.3×3.8

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